The Science of Colour

The Science of Colour

Rajini Rao wrote a great post about the science that informs the art of Georges Seurat. Rajini focused on Seurat’s style, Pointillism; I’ll expand on the colour theory behind this style. In the late 16th Century, Renaissance artists like Leonardo da Vinci started playing around with light on their canvases. Prior to this art was very dark and figures were starkly illustrated. People were painted against a dark canvas, as if they were rigid statues surrounded by darkness, and landscapes reflected stillness rather than movement.

So artists started working with various techniques such as sfumato (meaning to evaporate like smoke) which were developed through the artists’ scientific studies on light and dark in the natural world. The world’s most famous painting, The Mona Lisa is painted in this style. The painting has texture and depth created by small brush strokes and a bold use of lighter colours and shading. The effect leaves the viewer with the impression that her eyes follow you as you move around the painting. 

In the 19th century, the Impressionists took this colour play further, by using the scientifically informed writing by Michel Eugène Chevreul, Charles Blanc, Eugène Delacroix and others . For the first time in Western history, artists stopped using black to draw shadows and white to convey light. Thanks to new developments in science, these artists realised these black and white tones do not really reflect nature. Our eyes perceive nature to be vibrantly colourful, even in its shadows. So they adopted the colour wheel model we know today, with three primary colours (red, yellow and blue) being blended to create corresponding secondary colours (orange, green and purple). Each of these two sets of colours has complimentary colours that can be used to create a much more realistic illusion of shadow and light. The new colour theory added even more depth and complexity to artwork.

The artists developed their colour theory by working with scientific research about visual perception and by studying nature. They painted outdoors (“en plein air”) to capture the shifting light, in a way that was not customary for the day. The Renaissance artists and Impressionists presented their art theory as science. For example, Seurat talked about the light in his paintings hitting the retina (; more here 

Science has had a significant impact on art (and vice versa), but this relationship hasn’t always been well-received. The art of Seurat and his contemporaries, Manet, Monet, Renoir and other masters were derided at the time. Their art was dismissed by many as a “perversion.” Yet by using colours in this new method, paintings were more vivid and life-like.  

Professor Patrick Cavanagh notes that even as art is inspired by science, artists have taught us much about the how our brains make sense of visual information: “For science, we’re just fascinated by this process: Why things that are not real, like lines, would have that effect. Artists do the discoveries, and we figure out why those tricks work.” (

Learn More

* Historical development of colour wheel (3 part series)

* Michel Eugène Chevreul

* Charles Blanc

* Eugène Delacroix

Originally shared by Rajini Rao

The Art of Seurat: Science and Pointillism

After winding through the bucolic Dutch countryside, two bus loads of scientists were disgorged at the Kröller-Müller Art Museum in Otterlo, hoping for a dose of culture to leaven our week-long immersion in research (on ATP-driven pumps; To our delight, the museum was hosting the work of Georges Seurat, the master of pointillism. Fittingly, Seurat once said, Some say they see poetry in my paintings; I see only science

What’s the Point?: In contrast to traditional methods that mix pigments, pointillism is a technique where dots of pure color are applied, allowing the eye and the mind to blend the colors to give a richer and brighter effect. Although the term was first used to ridicule the technique, pointillism (also called divisionalism) gained credibility by the end of the 19th century, giving rise to neo-impressionism, cubism and modern art, and influencing other artists like van Gogh and Matisse.  Seurat’s most famous work showcasing pointillism is A Sunday Afternoon on the Island of La Grande Jatte – 1884 ( Estimated to be made up of ~3.5 million dots, it took nearly 2 years to complete!

 A closer look reveals individual dots of blue, green, yellow and even red in the water, which give the impression of changing, shimmering color as the viewer moves towards the canvas. Our brains blend the dots into a color that is not actually there.  When pigments are mixed, they absorb light. By avoiding mixing, there is no subtractive effect and colors appear brighter. The white canvas between dots enhances this effect. 

The inner rings in the animated circles a and b appear to be different colors: pink or orange. But it’s just an illusion – revealed when the surrounding circles are stripped away. Notice also that the color surrounding the inner circles in a and c, or b and d, is the same, but the frequency of concentric rings is different, altering our color perception.

Points to Pixels: Never could Seurat have guessed that the principles behind pointillism would be so widely used in modern technology- computer and television screens light up individual pixels colored in RGB (red, green, blue) and printers deposit CMYK (cyan, magenta, yellow, and Key or black) dyes. We are all pointillists now!

Slide show pdf on Seurat:


Watch: Seurat. Master of pointillism, Kröller-Müller Museum. A must see!

For a related post, see, Was Matisse a Neuroscientist?


2 thoughts on “The Science of Colour

  1. What an informative perspective and explanation on the science behind the evolution of artistic techniques! You also reminded me of a recent attempt to recreate Vermeer’s photorealistic techniques using cameras, mirrors and other optical gadgetry. (For lack of a better link:

    My only request (!) is that you share this to the science community as a standalone post, since Google+ unfortunately does not automatically include introductions with reshares. 


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